Curable composition

Abstract

Desirable properties required of curable compositions include: to have satisfactory storage stability; to give a cured product having a mat surface with almost no residual tack; to give a rubbery cured product having a low modulus and high elongation; and to give a cured product the surface of which is less apt to crack or discolor even in outdoor use. The present invention provides a curable composition which comprises: a vinyl polymer the main chain of which is a product of living radical polymerization and which contains at least one crosslinkable silyl group, and a primary and/or secondary amine having a melting point of not lower than 20° C. The curable composition of the present invention gives a cured product satisfying those properties.

1 . A curable composition 
 which comprises, as constituents, 100 parts by weight of a vinyl polymer (I) the main chain of which is a product of living radical polymerization and which contains at least one crosslinkable silyl group, and 0.1 to 20 parts by weight of a primary and/or secondary amine (II) having a melting point of not lower than 20° C.    
     
     
         2 . The curable composition according to  claim 1   wherein the vinyl polymer (I) has a molecular weight distribution of less than 1.8.    
     
     
         3 . The curable composition according to  claim 2   wherein a vinyl monomer constituting the main chain of the vinyl polymer (I) is mainly selected from the group consisting of (meth)acrylic monomers, acrylonitrile monomers, aromatic vinyl monomers, fluorine-containing vinyl monomers and silicon-containing vinyl monomers.    
     
     
         4 . The curable composition according to any one of  claim 3   wherein the main chain of the vinyl polymer (I) is a (meth)acrylic polymer.    
     
     
         5 . The curable composition according to any one of  claim 4   wherein the main chain of the vinyl polymer (I) is an acrylic polymer.    
     
     
         6 . The curable composition according to  claim 5   wherein the main chain of the vinyl polymer (I) is an acrylic ester polymer.    
     
     
         7 . The curable composition according to any one of  claim 6   wherein the living radical polymerization for producing the main chain of the vinyl polymer (I) is the atom transfer radical polymerization.    
     
     
         8 . The curable composition according to  claim 7   wherein a transition metal complex used as the catalyst in the atom transfer radical polymerization is one composed of a VII, VIII, IX, X, or XI group element in the periodic table as a central metal.    
     
     
         9 . The curable composition according to  claim 8   wherein the metal complex used as the catalyst is selected from the group consisting of a complex of copper, the one of nickel, the one of ruthenium and the one of iron.    
     
     
         10 . The curable composition according to  claim 9   wherein the metal complex used as the catalyst is a complex of copper.    
     
     
         11 . The curable composition according to any one of  claim 10   wherein the crosslinkable silyl group of the vinyl polymer (I) is represented by formula 1:     —SiY a R 3-a   (1)    (wherein R is an alkyl group containing 1 to 20 carbon atoms, an aryl group containing 6 to 20 carbon atoms, an aralkyl group containing 7 to 20 carbon atoms or a triorganosiloxy group represented by (R′) 3 SiO— (wherein R′ is a univalent hydrocarbon group containing 1 to 20 carbon atoms and the three R′ g roups may be the same or different) and, when there are two or more R groups, they may be the same or different; Y represents a hydroxyl group or a hydrolyzable group and, when there are two or more Y groups, they may be the same or different; a represents 1, 2 or 3).    
     
     
         12 . The curable composition according to any one of  claim 11   wherein the crosslinkable silyl group of the vinyl polymer (I) is at the terminus of the main chain.    
     
     
         13 . The curable composition according to any one of  claim 12   wherein the melting point of the primary and/or secondary amine (II) is 30 to 100° C.    
     
     
         14 . The curable composition according to any one of  claim 13   which contains, relative to 100 parts by weight of the vinyl polymer (I), 3 to 300 parts by weight of a crosslinkable silyl group-containing polymer (III), the molecular chain of which is substantially composed of alkyl acrylate monomer units and/or alkyl methacrylate monomer units and which is obtained by radical polymerization other than living radical polymerization.    
     
     
         15 . The curable composition according to any one of  claim 14   which further contains, relative to 100 parts by weight of the vinyl polymer (I), 0 to 1,000 parts by weight of polyoxyalkylene polymer (IV) containing at least one crosslinkable silyl group.    
     
     
         16 . The curable composition according to any one of  claim 15   which is free of polyoxyalkylene polymer (IV) containing at least one crosslinkable silyl group.    
     
     
         17 . The curable composition according to any one of  claim 16   wherein 0.1 to 20 parts by weight of a tin curing catalyst (V) is used per 100 parts by weight of the vinyl polymer (I).    
     
     
         18 . An adhesive 
 which is produced by using the curable composition according to any one of  claim 17 .    
     
     
         19 . A sealing material 
 which is produced by using the curable composition according to any one of  claim 17 .    
     
     
         20 . A liquid gasket 
 which is produced by using the curable composition according to any one of  claim 17.